Air line lubricator



March 24, 1970 c. A. HANSSON 3,502,178

AIR LINE LUBRICATOR Filed June 6. 1967 INVENTOR.

CARI Audens Hmssw United States Patent US. Cl. 184-55 4 Claims ABSTRACTOF THE DISCLOSURE An air line lubricator comprising a casingincorporating two bowl-shaped halves joined to one another along theirrim portions, a tube for the passage of compressed air therethrough andtraversing said casing across said rim portions, a portion of reducedcross section in said tube, a pressure conduit for feeding air underpressure into said casing, said pressure conduit being in fixedcommunication with said tube at a point spaced from said reduced portionthereof and extending in coiled relation to said tube along the innersurface portions of both casing halves, and a suction conduit forsucking oil into said tube, said suction conduit being in fixedcommunication with said reduced portion of said tube and extending incoiled relation to an axis transverse to said tube between opposed innersurface portions of said casing halves along the inner surface thereof,said suction conduit being perforated by a plurality of fine boresspaced there along and said pressure conduit being perforated by aplurality of fine bores spaced there along, said fine bores having adiameter of between about 0.75 and 2 millimeters.

An outwardly bulging hollow air line lubricator casing containing oil istraversed by a tube for compressed air connected to said air line.Within said casing the tube is connected to an air pressure transmittingconduit coiled about the tube and extending along the inner surface ofsaid casing and an oil suction conduit coiled about an axis transverseto said tube and extending between 0pposed inner surface portions ofsaid casing along the inner surface thereof.

This invention relates to air line lubricators and more particularly toan air line lubricator having a casing forming an oil chamber, a tubetraversing said casing for the passage of compressed air therethroughand communicating with the said casing on the one hand through apressure conduit for feeding air under pressure to said casing and onthe other through a suction conduit for sucking oil into said tube.

It is an object of the present invention to provide a rigid andlightweight lubricator which will stay tight and operate without failureduring rough working conditions for example while being dragged inbroken stone and squeezed by large forces.

Another object of the invention is to provide a lubricator having alarge flow capacity and a more nearly linear relation between the oildelivery or dosage and the air flow volume per unit of time as comparedto the usually quadratic relation between the differential pressurecausing the oil delivery and the air flow volume per unit of time.

A further object of the invention is to provide a lubricator the casingof which may be easily and cheaply manufactured of sheet metal parts bywelding.

With the above in view the invention consists in an air line lubricatorhaving a casing forming an oil chamber, a tube traversing said casingfor the passage of compressed air therethrough and communicating withthe said casing on the one hand through a pressure conduit for feedingair under pressure to said casing and on the other through a suctionconduit for sucking oil into said tube, characterized in that saidcasing is an outwardly bulging hollow body in which said pressureconduit is coiled about the tube and extends along the inner surface ofsaid casing while the suction conduit is coiled about an axis transverseto said tube and extends between opposed inner surface portion of saidcasing along the inner surface thereof.

The invention will be described more in detail by the aid of theaccompanying drawing in which FIG. 1 shows a longitudinal sectional viewthrough a lubricator according to the invention. FIG. 2 is a perspectivefragmentary view shown partly in section and partly exploded of thelubricator in FIG. 1. FIG. 3 shows a sectional view on line 33 in FIG.1.

The lubricator in the figures consists of an outwardly bulging flattenedbi-convex casing or hollow body 10 forming the oil chamber of thelubricator. The hollow body 10 is traversed by a venturi tube 11. At theopposite ends of the venturi tube 11 are welded inwardly threadedsleeves 12 into which are threaded coupling halves 13 and 14. The half13 is intended for being sealingly connected to a compressed air hosefor the delivery of compressed air, while the half 14 is connected to ahose leading to the compressed air consuming tool which shall besupplied with compressed air containing a suitable dosage of lubricatingoil.

The venturi tube 11 has its smallest section at the middle portionthereof and is connected at this point to an oil control valve housing15 including a needle valve 16. The needle valve 16 is threaded into theinner portion of the valve housing 15 and is adjustable axially thereinby screwing whereby an oil delivery bore 17 may be controlled whichcommunicates with the venturi tube 11. The outer end of the valvehousing 15 projects out of the hollow body 10 and is closed by athreaded plug 18.

The hollow body 10 consists of two bowl shaped halves 20, 21 joined toone another along the rim portion thereof by welding. The halves 20, 21preferably are rotationally symmetric with respect to a central axisperpendicular to the plane of division of the halves 20, 21. The halves20, 21 are furthermore provided with semi-cylindrical diametricallyarranged openings 22, FIG. 2, into which the sleeves 12 of the venturitube 11 fit and are received when the halves 20, 21 are welded to. oneanother along their rim portions and to the sleeves 12. The upper half21 is provided with a central opening 23 through which is passed the oilcontrol valve housing 15 and said upper half 21 is welded theretowhereby the lubricator becomes more rigid. The upper half 21 is alsoprovided with a threaded collar 24 for oil replenishment into which aplug 25 is threaded.

A pressure conduit 26 is fixed to and communicates with the venturi tube11 adjacent to the sleeve 12 intended for the coupling half 13. Thepressure conduit 26 is coiled about the axis of the venturi tube 11extending in upward direction from the venturi tube transverse orperpendicular thereto and being coiled along but spaced from the innersurface of the hollow body 10 for almost a full turn around the venturitube 11. The coil portion of conduit 26 is terminated by an upward openend 27. As illustrated in FIG. 3 the coiled portion of conduit 26 ispreferably disposed in a cross plane perpendicular to the tube 11 andcoincident with the center axis of the oil control valve housing 15.

A suction conduit 30 is connected as by welding to the bottom of thebowl half 20 and is coiled about the center axis of the oil controlvalve housing 15 following in slightly spaced relation the inner surfaceof the hollow body 10 by a coil which extends from the bowl half 20upward towards the bowl half 21. The upper end of suction conduit 30 isbent inwardly-downwardly and connected to the oil control valve housing15 for communication therewith upstream of the needle valve 16. Thesuction conduit 30 is provided with a plurality of fine radial bores 32spaced along the conduit and with a diameter between 0.75 and 2millimeters, for example 1.5 mm. in case of a suction tube having adiameter of 6 mm. The pressure conduit 26 may in similar manner beprovided with fine radial bores 33 of the same magnitude.

The flattened bi-convex shape of the welded hollow body 10 is reinforcedby the venturi tube 11 and the valve housing 15 and forms a lightweightrigid construction permanently enclosing and protecting the workingparts of the lubricator. Compressed air is supplied to the coupling half13 and the pressure thereof is transmitted to the interior of the hollowbody 10 via the pressure conduit 26 through the end 27 and the fineradial bores 33 thereof. In the narrow middle portion of the venturitube 11 adjacent the oil delivery bore 17 the compressed air flows withincreased velocity and at a correspondingly reduced pressure. The oil inthe hollow body 10 thus will be actuated by a differential pressurewhich, when the needle valve 16 is adjusted to the desired position inthe valve housing 15, via the suction conduit 30 draws oil at thedesired quantity through the bore 17 into the compressed air fiow in theventuri tube 11. In lubricators the oil quantity delivered per unit ofvolume of the compressed air flow should not follow the quadraticrelation which is in force between the pressure differential generatedin the venturi tube and the air flow volume per unit of time. The reasonfor this is that the oil delivery per unit of air volume in such caseswould become too large causing unnecessary oil losses. However, thanksto the fine radial bores 32 of the suction conduit 30 as proved bypractical trials, this quadratic relation is changed and one receivesinstead thereof an advantageous more linear relation between the oildosage and the air flow volume. This follows since during operation, oilrising in the suction conduit 30 will become mixed with air whichpenetrates into suction conduit 30 through the uppermost radial boreholes 32, said uppermost radial bore holes 32 being those disposed inthe air-filled dome portion of hollow body .10, and influence the oilflow relationship in the desired direction. The bores 32, 33 alsoefiectively eliminate generation of siphon action in the respectiveconduits 30 and 26. Unintentional emptying of the lubricator and itsconduits is hereby avoided when the lubricator happens to take anabnormal position. Thus when the line pressure is relieved while thehollow body 10 is positioned upside down, the air pressure within body10 will be immediately relieved through the then uppermost bore holes 33in pressure line 26. This prevents the air cushion trapped in hollowbody 10 from forcing large oil additions into the line conduits.

What I claim is:

1. An air line lubricator comprising a casing incorporating twobowl-shaped halves joined to one another along their rim portions, atube for the passage of compressed air therethrough an dtraversing saidcasing across said rim portions, a portion of reduced cross section insaid tube, a pressure conduit for feeding air under pressure into saidcasing, said pressure conduit being in fixed communication with saidtube at a point spaced from said reduced portion thereof and extendingin coiled relation to said tube along the inner surface portions of bothcasing halves, and a suction conduit for sucking oil into said tube,said suction conduit being in fixed communication with said reducedportion of said tube and extending in coiled relation to an axistransverse to said tube between opposed inner surface portions of saidcasing halves along the inner surface thereof, said suction conduitbeing perforated by a plurality of fine bores spaced therealong and saidpressure conduit being perforated by a plurality of fine bores spacedtherealong, said fine bores having a diameter of between 0.75 and 2millimeters.

2. A lubricator according to claim 1 characterized in that said casingis of flattened bi-convex shape with said bowl-shaped halves thereofbeing rotationally sym metrical.

3. A lubricator according to claim 1 characterized in that along saidtransverse axis there is affixed a valve housing to said tube projectingthrough and fixed to said casing, said valve housing including anadjustable oil control valve to which said suction conduit is coupled.

4. An air line lubricator comprising a casing incorporating twobowl-shaped halves joined to one another along their rim portions, aventuri tube for the passage of compressed air therethrough andtraversing said casing across said rim portions, a pressure conduit forfeeding air under pressure to said casing, said pressure conduit beingin fixed communication with said tube at a point spaced from the venturithroat thereof and extending in coiled relation to said tube along theinner surface portions of both casing halves, and a suction conduit forsucking oil into said tube, said suction conduit being in fixedcommunication with said venturi throat of said tube and extending incoiled relation to an axis transverse to said tube between opposed innersurface portions of said casing halves along the inner surface thereof,said suction conduit being perforated by a plurality of fine boresspaced therealong and said pressure conduit being perforated by aplurality of fine bores spaced therealong, said fine bores having adiameter of between 0.75 and 2 millimeters.

References Cited UNITED STATES PATENTS 1,657,597 1/1928 Terry 184551,688,946 10/1928 Terry 1845S 1,909,021 5/1933 Slater 18455 1,925,8269/1933 Terry et al. 184'55 2,073,009 3/1937 Hersey et al. 184552,204,950 6/ 1940 Rouse 184-55 2,585,457 2/1952 Gillerstrom 184552,607,441 8/1952 Gillerstrom 184-55 2,646,134 7/1953 Nickens 26178 XRMARK M. NEWMAN, Primary Examiner MANUEL A. ANTONAKAS, Assistant ExaminerUNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,502,178 Dated March 2 1970 Inventor(s) It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

' Column 1, lines 6 and 7 should read --C1aims priority,

application Great Britain, June 20, 1966, 27,508/66--.

SIGNED RND SEALED JUL 2 8 1970 am) mm 1:. sum. JR. Edwud H. mm. ItGomialioner or amt: Awaiting Officer

